JP2009009031A - Organic EL display substrate and method of manufacturing the same - Google Patents

Abstract

A substrate for an organic EL display device capable of easily removing excess organic EL material solution is provided.
A substrate body 101, an electrode 102 disposed on the substrate body 101, a bank 103 provided between the electrodes 102 for dividing the electrode 102 into stripes, and a signal provided at an end of the electrode 102 A substrate for an organic EL display device, characterized in that a projecting portion 105 is provided on a signal extraction electrode portion (right end electrode portion 104b) that is formed of an extraction electrode portion 104 and is in a positional relationship parallel to the bank 103. 1.
[Selection] Figure 1

Description

  The present invention relates to a substrate for an organic EL display device and a method for manufacturing the same.

  An organic electroluminescence element (hereinafter referred to as an organic EL element) is an element in which a light-emitting layer having EL light emission ability is composed of an organic low-molecular compound or an organic polymer compound. The organic EL element has ideal characteristics as an element constituting a display, such as a wide viewing angle due to self-emission, and excellent impact resistance. For this reason, research and development of organic EL elements are being promoted in various fields.

  Here, as a manufacturing method of the organic EL element, a vacuum deposition method, an ink jet method, a printing method, and the like are widely studied. These manufacturing methods are also used when manufacturing an organic EL display in which organic EL elements are integrated.

  The nozzle printing method, which is a kind of ink jet method, is a method in which an organic EL material dissolved in a liquid is used and a solution of the organic EL material is applied onto an electrode. Specific examples of the production of an organic EL display using this method include those disclosed in Non-Patent Document 1. According to Non-Patent Document 1, a liquid organic EL material can be separately applied by generating fluorine plasma in a vacuum device and applying liquid repellency to a bank formed of an organic material on a substrate. .

  In this case, the organic EL material may adhere to portions other than the bank. For this reason, as disclosed in Patent Document 1, it is necessary to remove the organic EL material attached by irradiating a laser beam on the electrode portion or the like after the coating process.

  In addition, in Patent Document 2, a physical obstacle is provided adjacent to the display unit so that the organic EL material applied by a printing method or a coating method does not spread out other than the display unit, and an electrode unit or the like. A method of protecting is disclosed.

  Furthermore, Patent Document 3 discloses a method of wiping off a portion where an organic EL material applied by a coating method adheres to a portion other than the display portion with a solvent.

JP 2006-164904 A JP 2004-288403 A JP 2004-152512 A 05 SID Digest P.M. 1192

  However, when the organic EL material that protrudes as disclosed in Patent Document 1 is to be removed by laser irradiation, the organic film peeled off from the substrate may contaminate the display portion. Further, the obstacle disclosed in Patent Document 2 cannot function effectively in a system in which liquid is continuously applied to the outside of the display portion as in the nozzle printing method. Further, even when the organic EL material is wiped off with a solvent as in Patent Document 3, when thickly applied, there is a risk that the thickly applied portion may be wiped off.

  The present invention solves the above-described problems, and an object of the present invention is to provide an organic EL display device substrate that can easily remove excess organic EL material solution.

  The substrate for an organic EL display device of the present invention includes a substrate main body, an electrode disposed on the substrate main body, a bank provided between the electrode and the electrode and dividing the electrode into stripes, and the electrode And a signal extraction electrode portion provided at an end of the bank, and the signal extraction electrode portion in a positional relationship parallel to the bank is provided with a protruding portion.

  ADVANTAGE OF THE INVENTION According to this invention, the board | substrate for organic EL display apparatuses which can remove an excessive organic EL material solution easily can be provided.

  In the organic EL display device manufactured from the organic EL display device substrate of the present invention, a protruding portion is disposed on the extraction electrode. As a result, when a solution containing an organic EL material is applied by a dispense (nozzle printing) method, the liquid agent does not adhere to the take-out electrode due to the liquid repellency of the protruding portion, or the portion to which only a very thin adhesive adheres Is formed. Thereby, the organic EL material adhering to the extraction electrode portion can be easily removed.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a plan view showing a first embodiment of an organic EL display device substrate of the present invention. The organic EL display device substrate 1 of FIG. 1 includes a substrate body 101, a pixel electrode 102, a bank 103, a signal extraction electrode portion 104, and a protruding portion 105.

  In the organic EL display substrate 1 of FIG. 1, the pixel electrodes 102 are arranged in a matrix on the substrate body 101. Each drive circuit is an active matrix type arranged (not shown) under the pixel electrode. The bank 103 is provided between the pixel electrode 102 and the pixel electrode 102, and divides the pixel electrode 102 into stripes. The signal extraction electrode unit 104 is provided around the pixel electrode 102. In the organic EL display substrate 1 of FIG. 1, the signal extraction electrode portions 104 are provided at the right end portion (right end electrode portion 104a) and the upper end portion (upper end electrode portion 104b), respectively. Here, a protruding portion 105 is provided on each electrode portion of the right end electrode portion 104 a that is in a positional relationship parallel to the bank 103.

  In the organic EL display substrate 1 of FIG. 1, a bank 103 is formed between pixel electrodes 102 of each color arranged in a stripe shape, and the pixel electrode 102 sandwiched between the banks 103 and 103. A solution of the organic EL material can be applied thereon.

  In the organic EL display substrate 1 of FIG. 1, the surface of the bank 103 and the protruding portion 105 is subjected to a liquid repellent treatment. In particular, when the protrusion 105 is subjected to a liquid repellent treatment, almost no organic EL material solution remains on the right electrode portion 104a.

  FIG. 2 is a plan view showing a state when an organic EL material solution is applied on the organic EL display device substrate of FIG. 1. When the organic EL material is continuously applied using a dispenser so as to draw a trajectory indicated by 106 in FIG. 2, the trajectory 106 overlaps with a part of the right end electrode portion 104a as shown in FIG. Sometimes.

  FIG. 3 is a diagram showing how the organic EL material solution adheres to the right end electrode portion 104a on the organic EL display device substrate of FIG. In FIG. 3, the right end electrode portion 104a has a protruding portion 105 subjected to a liquid repellent treatment. For this reason, even if the organic EL material solution 107 is dropped from the right side electrode portion 104a, the organic EL material solution 107 is repelled from the right side electrode portion 104a due to the liquid repellent effect of the protruding portion 105. As a result, almost no organic EL material solution 107 remains on the right end electrode portion 104a. Even if the organic EL material remains on the right end electrode portion 104a, the organic EL material can be thinned to such an extent that it can be removed from the right end electrode portion 104a by a known method.

  As a method of applying a liquid repellency treatment to the surfaces of the bank 103 and the protrusion 105, a method of mixing a water repellent with the material forming the bank 103 and the protrusion 105, and a liquid repellency treatment after forming the bank 103 and the protrusion 105. There is a method to apply. Specific examples of the latter water-repellent treatment include a plasma treatment method in which a gas containing fluorine or a fluorine compound is introduced, or a liquid repellent such as an organic silicon compound, a fluorine-containing silicon compound, or an organic fluorine compound is formed into a vacuum film or A method of forming a film by a coating method is known.

  The bank 103 and the protruding portion 105 may be made of different materials, but desirably both are made of the same material. Further, the bank 103 and the protruding portion 105 may be formed in different processes, but preferably both are formed in the same process. It can be said that it is a simple and optimal method to form both in the same material and in the same process.

  Resin materials such as polyimide, acrylic, and epoxy can be used as the material constituting the bank 103 and the protruding portion 105. Further, as a method for forming the bank 103 and the protruding portion 105, a coating method or the like can be used, but a patterning method is preferably used. As a specific patterning method, a photolithography method using a resin material having photosensitivity, a printing method, or the like is used.

  The height of the protruding portion 105 is desirably approximately the same as the height of the bank 103. This is the same whether the bank 103 and the protruding portion 105 are formed in the same process or in different processes. This is because liquid splashes do not affect the process of applying the organic EL material solution to the pixel electrode 102.

  The protrusions 105 are preferably staggered in a plane in adjacent pixel columns as shown in FIG. This is to prevent the solution of the organic EL material repelled by the protrusion 105 from collecting in a specific portion.

  As a constituent material of the substrate main body 101, a metal substrate such as glass, Si wafer, ceramic such as alumina, transparent resin, or stainless steel with an insulating film attached can be used.

  FIG. 4 is a plan view showing a second embodiment of the substrate for an organic EL display device of the present invention. The organic EL display device substrate 2 in FIG. 4 includes a substrate body 201, electrodes 202, banks 203, signal extraction electrode portions 204, and protruding portions 205.

  The electrodes 202 are arranged in a stripe pattern on the substrate body 201. Here, a passive matrix organic EL element substrate is shown. The bank 203 is provided between the electrodes 202 and 202, and divides each electrode 202 into stripes. The signal extraction electrode portion 204 is provided at the left end (left end electrode portion 204a) and right end (right end electrode portion 204b) of each electrode 202. The left end electrode portion 204a and the right end electrode portion 204b are in a positional relationship parallel to the bank 203, and a protruding portion 205 is provided on the electrode portion.

  In the organic EL display device substrate 2 of FIG. 4, by providing the protrusions 205 on the left end electrode portion 204a and the right end electrode portion 204b, each of the electrode portions is formed on the electrode portions in the same manner as the organic EL display device substrate 1 of FIG. Almost no solution of the organic EL material remains.

  When providing the layer which comprises an organic EL element on the board | substrate for organic EL display apparatuses of this invention, coating methods, such as an inkjet method, can be used. At this time, an organic EL material having a different emission color can be applied to each of the electrodes divided into stripes.

  When applying the organic EL material solution onto the organic EL display device substrate of the present invention, preferably, as shown in FIG. 2, the orbit 106 of the organic EL material solution is a signal provided with a protrusion 105. It overlaps with the extraction electrode part.

After one layer forming the organic EL element is formed, it is preferable to seal a portion other than the extraction electrode portion with a glass cap or a SiN _x film. This is because, after the sealing step, the organic EL material slightly remaining in the extraction electrode portion can be easily removed by wiping with an organic solvent, laser irradiation, or the like.

[Example 1]
A substrate for the organic EL display device shown in FIG. 1 was produced.

  First, indium tin oxide (ITO) was patterned in a portion corresponding to a display region on the glass substrate 101 to form a matrix pixel electrode 102 and a TFT circuit (not shown). Next, a signal extraction electrode 104 made of Al was formed on the right end and the upper end of the display area. At this time, the number of extraction electrodes was 100 for the right end electrode portion 104a and 300 for the upper end electrode portion 104b.

  Next, a photosensitive polyimide material (Toray Photo Nice) was applied on the pixel electrode 102. Next, a photomask having a pattern of the bank 103 and the protruding portion 105 was prepared. Next, light was irradiated to the photosensitive polyimide through this photomask. After irradiating light, the bank 103 and the protrusion part 105 were formed by carrying out a chemical | medical agent process. The number of extraction electrodes parallel to the bank 103 is the right end electrode portion 104a, which is 100.

Next, fluorine plasma treatment was performed with CF ₄ gas to make the bank and the dummy bank liquid repellent at the same time. As described above, an organic EL display device substrate was obtained.

  Next, this organic EL display device substrate was used to produce an organic EL display device. First, PEDOT / PSS was applied between the bank 103 and the bank using a nozzle printing device in the display area and the adjacent portion, and baked at 200 ° C. for 30 minutes to form a hole injection layer. At this time, the thickness of the hole injection layer was 30 nm.

  Next, a 2% by weight toluene solution of poly [2-methoxy, 5- (2′-ethylhexoxy) -1,4-phenylene vinylene], which is a polyparaphenylene vinylene derivative, is dropped every other line between the banks. did. Next, a 1% by weight xylene solution of poly (3-alkylthiophene) poly [3-alkylthiophene] was added dropwise between the banks to which the toluene solution of the polyparaphenylene vinylene derivative was not applied. Thereafter, an organic EL layer was formed by baking at 150 ° C. for 10 minutes. At this time, the film thickness of the organic EL layer was 100 nm.

Next, using a vacuum evaporation apparatus was deposited Cs ₂ CO ₃ to form an electron injection layer. At this time, the thickness of the electron injection layer was 3 nm. Next, Al was vapor-deposited to form an upper electrode. At this time, the film thickness of the upper electrode was 100 nm.

  Next, after moving from vacuum to an inert gas, a glass cap with a hygroscopic agent is adhered to the pixel portion to protect the pixel portion, and then the organic EL material remaining on the extraction electrode portion is removed from the ruby cell stick. And wiped with toluene. Thus, an organic EL display device was obtained.

  When the obtained organic EL display device was connected to an external drive circuit and operated, no defect occurred.

[Comparative Example 1]
In Example 1, the substrate for the organic EL display device shown in FIG. 5 was obtained by the same method as Example 1 except that a photomask having only the pattern of the bank 103 was used when irradiating the photosensitive polyimide with light. It was. The organic EL display device substrate 10 of FIG. 5 includes a substrate body 111, pixel electrodes 112, banks 113, and signal extraction electrode portions 114. 1 corresponds to the substrate body 101, the pixel electrode 102, the bank 103, and the signal extraction electrode portion 104 of the substrate 1 for the organic EL display device of FIG. 1 except that no protruding portion is provided in the right end electrode portion. This is the same as the substrate 1 for an organic EL display device. In addition, an organic EL display device was obtained in the same manner as in Example 1. Here, when applying the solution of the organic EL material, it was applied so as to draw the track 115 shown in FIG. As a result, as shown in FIG. 7, a thick organic EL layer film of the organic EL material solution 116 was formed on the right end electrode portion 114a. The performance of the obtained organic EL display device was evaluated in the same manner as in Example 1. As a result, 3% wiring failure occurred during operation.

[Example 2]
In Example 1, a substrate for an organic EL display device was prepared in the same process as in Example 1, and after forming a hole injection layer, an organic EL layer, an electron injection layer, and an upper electrode in order, the extraction electrode portion was made of stainless steel. A protective layer made of SiN was formed by CVD using a mask. In the CVD method, a mixed gas of NH ₃ , SiH _4, and N ₂ was introduced as a material gas into a film formation chamber, and film formation was performed at a pressure of 100 Pa and an RF power of 100 W. When the film thickness reached 5000 mm, the film formation was completed to obtain a protective layer.

After protecting the pixel portion with the protective layer, the extraction electrode portion was irradiated with energy of 1 J / cm ^{2 with} an ArF laser to remove the remaining material.

  Next, after aligning a single-sided adhesive resin film provided with an acrylic adhesive with a film thickness of 25 μm on a PET film with a film thickness of 100 μm in a region other than the extraction electrode part, using a laminating machine And laminated on the protective layer. An organic EL display device was obtained as described above.

  When the obtained organic EL display device was connected to an external drive circuit and operated, no defect occurred.

It is a top view which shows 1st embodiment in the board | substrate for organic EL display apparatuses of this invention. It is a top view which shows a mode when the solution of organic EL material is apply | coated on the board | substrate for organic EL display apparatuses of FIG. It is a figure which shows the mode of adhesion of the solution of the organic EL material in the right end electrode part on the board | substrate for organic EL display apparatuses of FIG. It is a top view which shows 2nd embodiment of the board | substrate for organic EL display apparatuses of this invention. 10 is a plan view showing an organic EL display device substrate manufactured in Comparative Example 1. FIG. It is a top view which shows a mode when the solution of an organic EL material is apply | coated on the board | substrate for organic EL display apparatuses produced by the comparative example 1. FIG. It is a figure which shows the mode of adhesion of the solution of the organic EL material in the right end electrode part on the board | substrate for organic EL display apparatuses produced in the comparative example 1. FIG.

Explanation of symbols

1, 2, 10 Organic EL display device substrate 101, 111, 201 Substrate 102, 112 Pixel electrode 103, 113, 203 Bank 104, 114, 204 Signal extraction electrode 104a, 114a, 204b Right end electrode portion 104b, 114b Upper end electrode portion 204a Left end electrode portion 105, 115, 205 Projection portion 106, 115 Orbit of application of organic EL material solution 107, 116 Organic EL material solution 202 Electrode

Claims (3)

A substrate body;
An electrode disposed on the substrate body;
A bank provided between the electrodes and dividing the pixel electrode into stripes;
A signal extraction electrode provided at the end of the electrode, and
A substrate for an organic EL display device, wherein a protrusion is provided on the signal extraction electrode portion in a positional relationship parallel to the bank.   2. The organic EL display device substrate according to claim 1, wherein the protruding portion is made of the same material as the bank and is manufactured in the same process as the bank.   3. When applying the organic EL material solution onto the organic EL display device substrate according to claim 1, the orbit of the organic EL material solution overlaps with the signal extraction electrode portion provided with the protruding portion. A method for producing a substrate for an organic EL display device.

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